Anti-FKBP prolyl isomerase family member 6 (inactive) antibodies are used for the immunodetection of the protein encoded by the FKBP6 gene. In humans, the canonical protein has a reported length of 327 amino acid residues and a mass of 37.2 kDa. Its subcellular localization is in the nucleus and cytoplasm. Alternative splicing is reported to yield 3 different isoforms for this protein. It is notably expressed in all tissues examined, with higher expression in testis, heart, skeletal muscle, liver, and kidney. A member of the FKBP6 protein family, it is known to have an essential role in spermatogenesis. The gene encoding this protein is implicated in Spermatogenic failure. Other names for this target antigen include SPGF77, inactive peptidyl-prolyl cis-trans isomerase FKBP6, 36 kDa FKBP, FK506 binding protein 6, 36kDa, FK506-binding protein 6, and FKBP36. Gene orthologs have been identified in the mouse, rat, bovine, frog, chimpanzee and chicken species.